Mask



FIG. 1 is a top, front, right side perspective view of a mask, showingmy new design;

FIG. 2 is a bottom, rear, left side perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a right side elevation view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof;

FIG. 9 is an enlarged portion view labeled, “FIG. 9,” in FIG. 2; and,

FIG. 10 is an enlarged portion view labeled, “FIG. 10,” in FIG. 5.

The details shown in broken lines form no part of the claimed design.

CLAIM The ornamental design for a mask, as shown and described.